A Dead Cert : Experiment 7
7. Newborn animals subjected to stress experiments, then killed
Cambridge, Newmarket and London
In a collaborative study, researchers from Cambridge, Newmarket and London subjected seven Welsh ponies and six Welsh Mountain lambs to surgery and stressful experiments soon after birth and again two weeks later.
Two to three days after birth, these newborn animals were anaesthetised and had a catheter inserted into a hind limb artery and vein, which was secured in place. Two days after surgery, the animals were placed in a custom-made sling for more than an hour, during which time they were injected with two different drugs. The first drug caused their blood pressure to rise suddenly and remain high for ten minutes. Blood pressure and heart rate were recorded. Once the blood pressure had returned to normal, the animals were given a second drug, which caused a sudden lowering of blood pressure. Blood samples were collected via the inserted catheters over a 30- minute period.
Two weeks later, the entire procedure was repeated on all of the animals. At the end of these experiments, the foals were re-homed with their mothers while the lambs were killed.
The authors note that the stress response in lambs is quite different to that seen in foals.
This study was supported by the Horserace Betting Levy Board.
O’Connor SJ, Gardner DS, Ousey JC, Holdstock N, Rossdale P, Edwards CMB, Fowden AL, Giussani DA. Pflugers Arch – Eur J Physiol 2005; 450:298-306. Development of baroreflex and endocrine responses to hypotensive stress in newborn foals and lambs.